Robotic Cable Inspection System

A successful cable inspection robot must overcome many obstacles: very narrow or tight spaces, restrictions on size and weight, wireless operation and adverse environmental conditions. The Robotic Cable Inspection System includes failure tracking, collision avoidance, and path planning. The robot is able to carry out its specific tasks autonomously once the operator has given an overview of the job.

The UW cable inspection robot is intended to be used with underground power cable systems. However, space enthusiasts know about another cable that will need to be rigorously tested - the cable for the space elevator. (The space elevator is a visionary concept dating from the turn of the 19th century; an ultra-strong carbon nanotube ribbon would stretch from the Earth into space.) Science fiction writer Arthur C. Clarke, writing in his 1978 novel The Fountains of Paradise provides a means for cable inspection - the "spider:"

The flimsy spider - a prototype test vehicle that looked like a motorized bo'sun's chair - had already made a dozen ascents to twenty kilometers, with twice the load it would be carrying now. There had been the usual teething problems, but nothing serious; the last five runs had been completely trouble-free.
(Read more about Clarke's space elevator spider)

Unfortunately for the protagonist of Clarke's novel, the "sensors" that examined the space elevator cable were provided by the person riding in it! Visual inspection is probably not enough for a real space elevator cable, and is certainly not enough for University of Washington engineers. The Robotic Cable Inspection System provides non-destructive measurement methods that are designed to determine the fault type, extent of fault, and aging status of the cable. The cable robot uses temperature, acoustic and electric field sensors in checking cables.

As far as the space elevator is concerned, work has already begun on a cable-climbing robot. The Liftport group has been testing their space elevator robotic lifter in the lab and in real world tests using a balloon-borne cable; other groups have participated in the Space Elevator Games. Effective inspection of the carbon nanotube space elevator cable is essential; see Space Elevator Downer for details on just how perfect the cable would need to be.